BUCHANAN from Glasgow

I am researching the Buchanan Family from Glasgow
Robert Buchanan (B 1787) was a Watchmaker and Jeweller He married Jean Allison (B 1791)
Children were Robert, David (1), John, David (2), James, Jean, Daniel, Henrietta, and Catherine
We believe some of the Family went to America and some to Australia
David Buchanan(1818-1879) married Margaret Jack of the Engineering family Turnbull Grant and Jack
They had 3 sons
David (1847-1931)
Robert (1849-1916)
John (1851-1895)
David Buchanan (1)came to Australia in 1852 to examine the possibilities of establishing a shipbuilding and repair service in Melbourne
He returned to Scotland to collect his wife and 3 young sons and they left Birkenhead for Australia in 1857
David Buchanan (2) was educated in Melbourne but returned to Scotland to serve his apprenticeship with the family firm
He married Barbara Belle Bowman of Cambuislang,she was the daughter of Thomas Bowman and Barbara Jack and they returned to Melbourne
I would be pleased to hear from anyone with connections I am a great great granddaughter of David and Barbara